Card Box Robot Chassis

[Raeven]

I have started the $50 robot. So far I have constructed a chassis from an old Deck Box (like the ones you put Yugioh cards into). So far the only electronics on it are the two mounted servos. I plan to house the battery and circuit board inside of the box. On the front of the robot are two holes for the photo-resistors. However, having the two photo-resistors so close to the ground; inevitably, leads to them looking at their own shadow. I would like to know could this lead to a problem?

Here is a link to the deck box I used: http://www.criticalgamers.com/archives/pictures/DeckBox.jpg
The two holes are drilled into the white tab on the top of the box.

[dellagd]

well, it might. Depends on how close they are to the ground an if they are pointing down.

Have you put together the $50 board yet? Just try it out! If it does interfere, move them up!

[chelmi]

However, having the two photo-resistors so close to the ground; inevitably, leads to them looking at their own shadow. I would like to know could this lead to a problem?

I think you misunderstood how photo-resistor work. They don't "look" at something, they sense the light hitting their surface. I don't see how they could project a shadow on themselves.

[Raeven]

Pointing them at the ground allows them to read the light that reflects off the ground onto their surface.

[Razor Concepts]

Add LEDs to shine at the ground, getting rid of the shadows.

[random robots]

Add LEDs to shine at the ground, getting rid of the shadows.

wouldn't the led interfere with the readings from the ambient light?

[Razor Concepts]

Add LEDs to shine at the ground, getting rid of the shadows.

wouldn't the led interfere with the readings from the ambient light?

That brings us around to the question, why would you would you want to measure the ambient light of the ground    I assumed that by measuring the light reflected from the surface you wanted to do line following.

[random robots]

i was thinking it was a photovore. whoops

[dellagd]

can you not just move the photo resistors higher up on the robot?

point then up?

[Xyver]

or like a 45 degree angle forewards?  then itll look a few centimeters infront of your bot, instead of beneath it.

[WhomBom]

just a loose remark from a fellow just-started robot builder; don't try to cramp too much parts into a small space! you'll always forget something and than you will be happy with a bit of extra space 

[Alfa_Zulu]

as you might notice most light sources come from above, off the top of my head we have, the sun, lights in a house, torch and etc.

so point them almost straight up, if it drives into a shadow under a table it'll still turn around. this will cause your reading to be more accurate and less chance of it not sense the light at all